Identity-Based Matchmaking Encryption with Enhanced Privacy Against Chosen-Ciphertext Attacks

Sohto Chiku; Keitaro Hashimoto; Keisuke Hara; Junji Shikata

Paper 2023/1435

Identity-Based Matchmaking Encryption with Enhanced Privacy Against Chosen-Ciphertext Attacks

Sohto Chiku

, Yokohama National University

Keitaro Hashimoto

, National Institute of Advanced Industrial Science and Technology

Keisuke Hara

, The University of Osaka

Junji Shikata

, Yokohama National University

Abstract

Identity-based matchmaking encryption (IB-ME) proposed by Ateniese et al. [CRYPTO 2019; Journal of Cryptology 2021] enables users to communicate privately, anonymously, and authentically. Following the seminal work of Ateniese et al., considerable research has been conducted on the security and construction of IB-ME schemes, but no scheme with enhanced privacy against chosen-ciphertext attacks is known. In this paper, we propose two IB-ME schemes that simultaneously achieve enhanced privacy against chosen-ciphertext attacks. The first scheme is built on the bilinear Diffie–Hellman assumption in the random oracle model. Inspired by the scheme of Ateniese et al., our construction attains stronger security guarantees while providing more compact decryption keys and ciphertexts than the scheme of Ateniese et al. The second scheme is a generic construction built upon anonymous identity-based encryption, digital signatures, NIZK systems, and reusable extractors. This scheme is obtained by generalizing the specific scheme of Francati et al. [INDOCRYPT 2021] with several technique to solve CCA-related issues. It constitutes the first IB-ME scheme achieving the stronger security notions in the standard model. As an additional contribution, we classify existing authenticity notions for IB-ME into four categories—no message attacks (NMA) and chosen message attacks (CMA), each considered against both insiders and outsiders. This taxonomy enables a precise comparison among existing IB-ME schemes.

Note: Fix technical flaws in the generic construction of IBME.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Preprint.
Keywords: Identity-Based Matchmaking Encryption Security Model Pairing-Based Cryptography Generic Construction Post-Quantum
Contact author(s): chiku-sohto-tw @ ynu jp
keitaro hashimoto @ aist go jp
hara-keisuke-kj @ ynu ac jp
shikata-junji-rb @ ynu ac jp
History: 2026-07-06: last of 7 revisions; 2023-09-21: received; See all versions
Short URL: https://ia.cr/2023/1435
License: CC BY

BibTeX

@misc{cryptoeprint:2023/1435,
      author = {Sohto Chiku and Keitaro Hashimoto and Keisuke Hara and Junji Shikata},
      title = {Identity-Based Matchmaking Encryption with Enhanced Privacy Against Chosen-Ciphertext Attacks},
      howpublished = {Cryptology {ePrint} Archive, Paper 2023/1435},
      year = {2023},
      url = {https://eprint.iacr.org/2023/1435}
}